The environmental impact and sustainability of plantations in Sub-Saharan Africa: Ghana's experiences with oil-palm plantations

(introductory text...)

Introduction

Overview of the plantation system in the Sub-Sahara

The evolution of plantations in Ghana

The positive impacts of the plantations

Adverse environmental impacts and sustainability

Conclusion

References

Adverse environmental impacts and sustainability

However, the question is whether the gains can be sustained. An answer was
sought by examining the plantations' adverse impacts, particularly on the
natural environment.

Traditionally, the natural environment, including the land, has constituted
the basis of the farming, hunting, and gathering economies in the plantation
areas. Consequently, the expropriation of over 16,000 ha of peasant lands for
the plantations, with little or no compensation for the cottages, camps, and
farms lost, together with various land-use or proprietary rights, could be
expected to precipitate social resistance. This, indeed, had been the case, as
illustrated by the dramatic refusal of the migrant Ningo farmers of Atobriso and
Okaikrom to grant government and GOPDC officials entry into their acquired land.
As in the case of land expropriated for the RISONPALM nucleus estate in Nigeria
(Gyasi 1987,1990), other manifestations of the peasants' resistance had
included: a group petition to the government and to the management of the
plantations; threatened court action; pilfering of palm fruit from the
plantations; and acts of sabotage, which had necessitated a tightening of
security at considerable cost to the plantation companies. The insecurity
engendered by the compensation factor partly accounts for the companies'
inability to establish effective control over portions of their concessions used
illegally by land-short local people, including squatter farmers.

But perhaps the most serious adverse effect has been the rapid transformation
of the forest ecosystem and its resilient diversified ecologically based
traditional economy into a vulnerable artificial monocultural system.
Instability, risks, or uncertainties are inherent features of the natural
environment, which the peasant farmers recognize. Traditionally, the peasants
try to minimize these environmental risks, combat soil erosion, optimize
utilization of the different soil nutrients, and enhance food security by
intermixing crops of varying degrees of environmental sensitivity and different
nutritional value, and by other forms of agricultural diversification and risk
minimization. The resilient, diversified indigenous agriculture, modelled on the
forest ecosystem and based on eco-farming principles borne out of the peasants'
intimate knowledge of the natural environment, is being replaced by the
risk-prone monocultural system, with devastating consequences for the forest
ecosystem.

Of a sample of farmers, 47 per cent perceived a trend towards palm
monoculture as a result of the activities of the plantation companies in their
locality; 62 per cent of the farmers considered the monocultural trend
desirable, because they saw the palm as lucrative, dependable, and a steadier
income-generator owing to the high value placed on it, its robust character, and
its bi-monthly fruiting habit. However, a significant 38 per cent of the farmers
did not consider the trend towards palm monoculture desirable, primarily because
it was leading to shortages of local staple foods, a problem also reported by
the management of the plantations. A second reason was the vulnerability of the
monocultural palm farms to insect pests and diseases (table 18.1), an
agro-ecological problem most vividly demonstrated by the unusually massive and
destructive insect invasion of the monocultural palm farms in 1986-1987. A third
reason was the difficulty of marketing palm fruit and oil associated with poor
marketing facilities for the increased output, and the higher production cost in
Ghana, related to the less favourable moisture conditions and less effective
radiation utilization by the palm (BOPP 1990), which has led to the growing
premature felling of the palm trees for production of the local gin, akpeteshie.
Other reported or observed adverse effects were:

· deforestation, and the associated growing cost and scarcity of forest
products such as "bush meat" (game), medicinal plants, and wood, an
important constructional material and the basic fuel source;

· the high cost, erratic supplies, and polluting effect of the agrochemicals
used to boost palm yields and to control pests and weeds, especially in the
large plantations;

Although these reports or observations require further investigation, they
nevertheless point to the environmental shortcomings of the system.

On the one hand, the plantation system, especially the nuclear estate
version, appears attractive as a development strategy in the Sub-Sahara because
of its ability to accelerate agricultural production and generate other
important socio-economic benefits, including employment, income, agro-industrial
growth, and modern infrastructure, especially in the rural areas. On the other
hand, the system does not appear attractive because its vulnerable character and
adverse effects on traditional landholding and land-use rights, on food and fuel
security, and, above all, on the natural environment throw its sustainability
into serious doubt.

Perhaps the plantation system might be rendered sustainable by encouraging
its modification into smaller diversified farms on the basis of organic and
other eco-farming and the principles of low external inputs that underpin proven
sustainable systems such as modern agro-forestry and traditional African
systems, notably:

· the bush fallow system, which intermixes diverse crops amidst selected
uncleared trees and bushes in the form of proto-agroforestry;

· the more or less permanent farming system on compound land, which often
integrates both livestock and assorted crops around the household or living
compound (Benneh 1972; Benneh and Gyasi 1991; Gyasi 1992b; Kopke and Schulz
1992).

Table 18.1 Insect pests and diseases of the oil-palm

INSECT

Scientific name

Common name

Category

Coelaenomonadera minuta (Coleoptera: Hispidae)

Oil palm leaf miner

Primary
pest

Pimelophila ghasquieri
(Lepidoptera: Pyralidae)

African spear
borer

Primary pest

Temoschoita quadripustulata (Coleoptera:
Curculionidae)

Oil palm weevil

Primary pest

Phynchophorusphoenicis (Coleoptera: Curculionidae)

Red striped weevil

Primary pest

Oryctes
spp. (Coleoptera: Dynastidae)

Rhinoceros
beetle

Primary pest

Latoia viridissima (Lepidoptera: Limacodidae)

West African slug caterpillar

Secondary pest

Zonoceros variegatus (Orthoptera: Acrididae)

Grasshopper

Secondary pest

Augosoma contaurius (Orthoptera:
Dynastidae)

N.A.

Secondary pest

Adoretus
umbrosus (Coleoptera: Dynastidae Rutelidae)

N.A.

Secondary pest

Schizonycha africana (Coleoptera:
Nololunthidae)

N. A.

Secondary pest

Parasa
viridissima (Lepidoptera: Limacodidae)

West
African slug caterpillar

Secondary pest

Spodoptera litura (Lepidoptera:
Noctuidae)

N. A.

Secondary pest

Phenacoccus spp. (Hemiptera: Coccoidea)

Mealy bug

Secondary pest

Pinnaspis marchali (Hemiptera:
Coccoidea)

Scale insect

Secondary pest

Sufetula
nigrescens (Lepidoptera: Pyralidae)

Oil palm
aerial root

Potential pest

Metisa plana (Lepidoptera: Psychedae)

Oil palm bag worm

Potential pest

Leptonatada siostedti (Lepidoptera: Notodontidae)

N. A.

Potential
pest

Monolepta apicicornis
(Coleoptera: Chrysomelidae)

N.A.

Potential pest

DISEASE

Anthracnose

Cercospora
leaf spot

Blast

Source: Gyasi (1991). N.A. = not available.

The principles underlying the native African systems have much to recommend
them because they derive from intimate knowledge of the local environment, form
an integral part of the traditional culture, and, as such, offer a strong basis
for agricultural development. Other possibilities for improving the
environmental impact and sustainability of plantations include the
"i'th" or "n'th" row method whereby every second, third,
etc. row in the plantation is reserved for crops other than the primary
plantation crop. Another is the arrangement whereby the outgrowers and the
smallholders devote a portion of their land to the industrial crop required by
the nuclear estate mill and the rest to food or other crops. Others include the
intermixing of the principal plantation crop with other
crops.